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June 19, 1928. 1,67434f M. SCHWARTZ MULTIOFFICE AUTOMATIC TELEPHONESYSTEM Original Filed Feb. 8, 1924 8 SheetSSheet l 1719.4 Wm? Af (m,

i n F2574 .F 1g:3 0- Tm June 19, 1928.

1,674,134 M. SCHWARTZ MULTIOFFICE AUTOMATIC TELEPHONE SYSTEM OriginalFiled Feb. 8, 1924 8 Sheets-Sheet 2 June 19, 1928.

M. SCHWARTZ MULTIOFFICE AUTOMATIC TELEPHONE SYSTEM a, 1924 sheet #sheets origina lF'led Fe Michael 'E chmar'z' d W7 June 19, 1928. R,674,134

M. SCHWARTZ MULTIOFFICE- AUTOMATIC TELEPHONE SYSTEM original Filed Feb.e, 1924 s sheets-sheet 4 Junev 19, 1928.

M. SCHWARTZ MULTIOFFICE AUTOMATIC TELEPHONE SYSTEM 8 SheeTs-Sheet 5-Imfen arf- Mchael Schwarlz' June 19, 1928. ,674,134

M. SCHWARTZ MULTIFFICE AUTOMATIC TELEPHONE SYSTEM Original Filed Feb. 8,1924 8 Sheets-Sheet 6 MEZ-zaal Schwarz Jne 19, 31928. 1,674,134

M. SCHWARTZ MULTIOFFIQE AUTOMATIC TELEPHONE SYSTEM Original Filed Feb.8, 1924 fda .724 f4;

H2L-gael Schwer-2z June 19, 1928. I l l,674l34 M. SCHWARTZ MULTIOFFIEAUTOMA'TIC TELEPHONE SYSTEM Original Filed Feb. 8, 1924 8 Sheets-S1166?,8

MaI-zaal. EchME/IZz i EnH- Patented .lune 19, 1928.

uairsnsra'rss lidde .L .maar aerien.,

MICHAEL SCHWARTZ, OFCHICAGO, ILLINOIS, ASSIGNOR, BY MESIIE ASSIGNMENTS,TO

AUTOMATICELECTRIC INC., OF CHICAGO, ILLINOIS, A CORPORATION OF DELA-WARE.

MULTIOFFICE AUTOMATIC-TELEPHONE SYSTEM.

i Application led February 8, 19211, Serial No. 691,327. Renewed October24, 1927.

The present invention relates to multioliice automatic telephone systemsin general, but is concerned more particularly with lsys'cms of theabove character in which call direc'- tors are employed to register,translate, and retransmit the part of the number which is indicative ofthe ofiice called, and the broad general object, briefly stated, may besaid v to consist in the provision of new and 1mproved circuitarrangements whereby the subscriber digits (the part of a numberindicative of the desired line in the particular office called) of atelephone number may be translated also and in such a manner that thecapacity of a given train of automatic step by step switches may beincreased so as to accommodate a larger number of subscribers without`increasing the number of switchesin the train.

There are many other objects, several of which are more or lessincidental to the carryingl out of the main object, all of which will bebest understood from a further perusal of the specification.

Referring now to the drawings comprising Figs. 1-12, inclusive, Figs. 14, inclusive, show four trunking layouts which are to be usedin'explaining the objects and fea-A tures of the invention, while Figs.5-11, in-

ratus employed in a telephone system em-V bodying the principles of theinvention to enable the invention to be understood andv its utilityappreciated, and Fig. 12 shows how Figs. 5-11, inclusive, should beplaced together. l

Referring now to Figs. 1-4, inclusive, Fig. l is a representative layoutof a 10,000-line oiiice employing the standard ten-level selectors. Onlyfive levels, however, of the thousands selectors are used and thecapacity of the oliice, which accordingly would otherwise be only 5,000lines is brought back to 10.000 lines by the use Vof CO0-lineconnectors. Fig. Qshows a layout of vtwo 10,000 line otiices in whichthe same thousandsV and hundreds selectors are used for both oiiices; inwhich 200-line connectors are used, as in Fig. 1; and in which thehundreds selectors are of the twenty-group type instead of the ten-grouptype shown in Fig. 1.

Fig. 3 is a. layout of a 10.000-1ine office wand is somewhat similar toFig. 1, except that twenty-group hundreds selectors. are

y sented by the hundreds selector F.

used insteadof the 20D-line connectors shown in Fig. 1.

Fig. l is a layout similar to Fig. 3, eX cept that the capacity of theconnectors shown in Fig'. 3 has been increased to 200 lines and thesecond or lower half of the connector banks is used to accommodate asecond 10,000 line oliice.

Referring now more particularly to Fig. 1, the lirst live levels of thethousands selector E are used to trunk calls to ve groups of hundredsselectors, one of which is repre- The ten levels of the hundredsselector F are used to trunk to ten groups of 20G-line connectors, ofwhich one group is represented by the QOO-line connector H.-

Reg'arding the necessary translation in the telephone numbers, which ofcourse are listed in the directory and called according to the decimalsystem, it may be pointed out that in case the thousands digit isanything from 1 to 5, inclusive, it is not translated, but if thethousands digit is anything from 6 to 0, inclusive, live is subtractedfrom it, or in other words, the digits 6 to 0, inclusive, are combinedwith the digits 1 to 5, inclusive.

. At this time it may be pointed out. that,

since only live levels of the selector E are used to trunk calls to10,000 lines. each of the live following groups of switches handles morecalls than if ten levels of the selector E were used to handle the sainenumber of calls. In this way, a considerable saving in the total numberof switches can be made owing to the increased trunking eliiciency thatis made possible whenever two relatively small groups can be combinedinto one larger group. v

Regarding the translation necessary in order to choose between the twowipers of the connector H, it may! be pointed out that the of banks onthe connector H that are used depends upon the thousands digit. lf thisdigit is anything from 1-5, inclusive, the upper set of banks of theconnector H' is used, while if this digit is anything from 6 0,inclusive, an artificial series of eleven impulses is sent to theconnector H after the vertical movement and before the regular.numerical rotary movement, resulting in the wipers of the connector Hwhich cooperate with the upper bank being rotated entirely over thebank, ot @elated-S, resulting the wipers of the lower bank (which areset at such an angle that they are not brought into operative relationwith the associated bank contacts unless the eleven preliminary `rotarysteps are taken by the switch shaft) being brought into position readyto be rotated over the )ank as soon the next and last series oi`.impulses is delivered.

In summing up the layout of Fig. l, it m ay be point-ed out that tenseparate groups of numbers are combined into live compositegroups,'represented by the iirst live levels of the regula-r series otimpulses which operates it to select a trunk, the circuit :wrange mentsbeing such that ill ol'lice No. 2 is called the wiper-selecting digit isz and the upper bank is used, while itl oilice No. il is willed, thewiper-selecting digit is 3 and the lower bank oit selector F is used.

Referring now particularly to F ig. 3, it may be pointed out that thethousands digits "60, inclu-sive. when this ollice is called, arecombined with the thousands digits L5, inclusive, respectively, in themanner pointed out above in connection with Fig. l. In the layout shownin Fig. 3, however, the thousands digit controls the sending` out oi"the wiper selecting digit to the hundreds selec tors, such as theselector F2, instead of conl trolling the sen-ding out ot a preliminarywiper-selecting series of eleven impulses to pick out connector wipersas in the case o Fig. l. It is thus seen that the scheme shown in Fig.l, and the scheine shown in Fig. 3 are simply two di'l'lferent methodsol obtaining the same result as regards the capacity of the switchtrain, and it may be pointed out that the tra'liic conditions may besuch in one oii'ice as to make the use ot one layout expedient. whilethe traido conditions in another ol'liee ot the same system may be suchthat the use oit the other layout is more economical, or it may evenhappen that two stead of the 10G-line type. In this latter case, onebank of any one connector, such as H5 l'or example, represents lines inone office, while the other bank ot the same connector represents linesin a different oilice. f Accordingly the sending out of the preliminaryseries of eleven impulses between the vertical movement and the regularrotary movement of the connectors is controlled according to which otthe two offices is called.

It. may be pointed out at this time that the capacity of any one of thefour trains oi switches shown in Figs. l-Lhinclusive, may be doubled.When this is done, the trailic to the hundreds selectors and connectorsshown is handled in the same way as described hereinbefore and, inaddition, the upper live levels of the thousands selectors, instead ofbeing lett dead, are used to trunk calls through a new group of hundredsse-k lectors and thence by way of the connectors to the called lilies.After this is done, when a number is called which must be reached by wayolf one ot the upper live levels ol a thousands selector, the thousandsdigit is sent out untranslated in case itis any digit Ylrom t3 to O,inclusive, but translated in case it is any digit Jfrom l to 5,inclusive, the translation being such that the thousands digit l becomesa 6; the thousands digit 2 becomes a 7 etc. Accordingly, when either ofthe layouts shown in Figs. Q and '4i is lused tor both halves of theVthousands selector banks, four 10,000-line ollices located in the samebuilding may be accommodated with one set of thousand selectors and.with only three local switches involved in any one connection. Y

Referring now to Figs. 5-11, inclusive, Figs. 5, 6, and 7 show theswitching equipment employed for a connection Lfrom the line ofsubstation A, Fig. 5, to either of the -two substations, A or A2, Fig.7, whichsubstations are also represented in Fig. 2 as accessible to theconnector'I-Ig; and Figs. 841, inclusive, show by means ot the usualcircuit diagrams one of the call directors employed in making thenecessary translation both in the ottico digits and the subscriberdigits ot the numbers.

Fig. 5 shows the line switch C in which the line ot' substation. AYterminates and also the trunk circuit TC. which is one ot' the trunkcircuits accessible to the line switch C. This trunk circuit isindividual to the selector D and has associated with itfthe secondaryswitch SS which selects an idle di rector when the trunk circuit TC istaken -for use.

F 6 shows the thousands selector `E which is denoted in this drawing bymeans of the dottedrectangle bearing that reference character. Theselector E is accessible to the selector D,'Fig. 5, and has access tosecond selectors of which the selector F is liti) lli) one. The trunliugmay ie readily appre ciated by referring baclr to Fig. 2.

Fig. 7 shows the 200 lineconnector H2 whose upper wipers 251-253,inclusive, are used to complete the connection when the ele-venpreliminary rotary steps are not tal-:en by the switch shaft. rllhelower set wipers 261-263, inclusive, are used to complete the connectionin case the eleven preliminary rotary steps are taken. The fact that thelower wipers are set at an angle-with the banks is indicated.diagramn'iatically in the drawings.

Referring now particuarly to the director shown in Figs. 8411,.inclusive, the portion of the director shown in Fig. 8 comprises theimpulse-control sequence switch S and the associated relays 301 and 302,together with the stop#conductor-control sequence switch S; the portionof the director shown in Fig. 9 comprises the sending switch SEN,together. with the associated relays 40S-405, inclusive, andthe releaserelay 402; the portion of the director shown in Fig. 10 comprises theintermediate distributing frame DF, the `oliice register OR, and theassocated relays 5214525, inclusive; and the portion of the directorshown in Fig. 11 com nises'the digit registers`DR,-1-DR.4,inclusive,togeth1r with the translating relays 609 and 610.

The present system, having been thus described generally, will now bedescribed in connection with a detailed descriptioniof the operation ofthe apparatus shown For this purpose it will be assumed that thesubscriber at substation A,` Fig, 1, desires to converse with thesubscriber at substation A', Fig. 7. As far as the present invention isconcerned, the part of the number designating the desired office isimmaterial and no particular number will be assigned. rFhe part of thenumber, however, which indicates the desired subscriber after the ofliceis reached`v is 5,000, as=may be seen in Fig.

Accordingly, the subscriber at substation A; removes his receiver anddials the two oihce digits of the number, followed by the foursubscribers digits 5 i O O-,0.

`S/lhen the receiver is removed at substation A, line relay of the lineswitch C energizes over line conductors 11 and 12 and places ground onprivate normal conductor 13 at armature 20, thereby making the call ingline busy immediately and closing. a

circuit through switching relay 14 and stepping magnet 16 in series.

Line relay 15 also connects step test wiper 23 to the junction ofswitching relay 14 and stepping magnet 16 at armature 21. In case thetrunk upon which the wipers of the line switch are standine' is idle,switching relay 14 venergizes rie'ht away andseizes the said trunk.Assuming the trunk to be busy, however, there is a ground potential uponthe test conductor thereof, and this ground potential is extendedthrough test wiper to the junction of switching relay 14 and steppingmagnet 16. Switching relay 14 is accordingly short circu-ited and doesnot energize, and stepping magnet 16 operates in a buzzer-like mannerand advances the wipers 22-24, inclusive, step by step in search of anidle trunk.

Tfhen an idle trunk is reached, which trunk, it will be assumed, is theone comprising conductors 25-27, inclusive, switching relay 14, being nolonger short circuited, energizes. Stepping magnet 16, however, does notenergize at this time on .account of the high resistance of switchingrelay 14. Upon energizing, switching relay 14 opens` the test circuitand prepares the holding circuit at armature 1S, thereby making theseized trunk busy immediately; and at armatures 17 and 19 disconnectsthe line conductors 11 and l2 from the winding of line relay 15 andground at armatures 17 and 19 and eX- tends' them by way of'wipers 22and 24, conductors 25 and 27, and armatures 43 and and their restingcontact-s to the windings of line relay of the trunk circuit TC. Linerelay 35 thereupon energizes over the calling line and closes a circuitfor release relay 216 at armature 38. Release relay 36, upon energizing,places ground on release trunk conductor 26 at armature 40, therebycompleting the holding circuit for switching relay 14 of the line switchC before the slow acting line relay 15 has had time to deenergize. As a'tui-ther result of the energization of release relay 36 of the trunkcircuit TC, it closes at armature 41 a circuit through switching relay46 and stepping magnet 47 of the secondary switch SS in series, and atarmaturer42 connects test wiper 54 to the junction of switching relay 46and stepping magnet 47. lAccordingly, the switch SS selects an idletrunk inithe same manner` as above pointed out for the line switch C. Inthis case it will be assumed that the director shown in the drawings isthe first one found to be idle. Accordingly, when the wipers 52455,inclusive, of the secondary switch SS arrive upon the bank contacts inwhich the conductors 5659, inclusive, terminate, switching relay 46energizcs; opens the test circuit and places ground on test wiper 54 atarmature 50; connects up the impulse wiper 55 at armature 51; and atarmatures 48 and 49 connects up wipers 52 and 53, thereby placing abridge across conductors 62 and 64 of the selector D. This bridgeincludes wipers 52 and 53 of the secondary switch SS, conductors 56 and57 and armatures 41S and 421, Fig. 9, and their resting contacts inmultiple. Line relay of the selector D accordingly energizes and closesa circuit for release relay 66 at armature 7 6. Release relay 66 there-IVN) secondary llO upon energizes and places a multiple ground onrelease trunk conductor 63 at armature 77, and at armature 78 opens apoint in the circuit of release magnet 71 and prepares a ture 415 opensthe normal restoring circuit of the sequence switch S.

The above described operations have all taken place responsive to theremoval of the receiver at substation A, and the apparatus is now inreadiness to receive the first ollice digit in the desired number. lVhenthe subscriber at substation A manipulates his calling device inaccordance with the first ollice digit, a corresponding number ofinterruptions are produced in the circuit of line relay oit' the trunkcircuit TG, and each time line relay deenergizes responsive to one ofthese interruptions, it closes at armature 39 a circuit for verticalmagnet 504 of the oflice register OR, Fig. 10, as `follows: from groundby way of the resting Contact and armature 39, armature 51 and itsworking contact, wiper 55, conductor 59, series relay 301, Fig. 8, wiper310 of the sequence switch S, the h'rst associated bank contact,conductor 321, and the vertical magnet 504, Fig. 10, to battery. By theoperation of the vertical magnet 504, the wipers 511-514, inclusive, ofthe oflice register OR are raised step by step until they come to restopposite the desired level et bank contacts. Relay 301, Fig. 8, isenergized in series with vertical magnet 504 upon the Ii rst impulse ofcurrent delivered to the latter, and, being slow acting, maintains itsarmature 304 attracted throughout the entire series of impulses. Uponenergizing, relay 301 closes a circuit for slow acting relay 302 whichaccordingly energizes and preparcs at armature 305 a circuit forstepping magnet 306 ot the sequence switch S.

At the end of the series oi impulses delivered to the vertical magnet ofthe office register, series relay 301 deencrgizes and opens the circuitof slow acting relay 302, and at the same time closes the circuit ofstepping magnet 306 of the sequence switch S, whereupon the wipers 309and 310 of the sequence switch S are advanced into engagement with thesecond set of bank contacts. An instant later, slow acting relay 302 deenergizes and opens the circuit of stepping magnet 306 at armature 305.

When the calling subscriber at substation A manipulates his callingdevice in accordance with the second office digit, a correspondingseries of impulses is delivered over the circuit above traced, to wiper310 of the sequence switch S, Fig. 8, and thence by way of conductor 322to rotary magnet 503 of the office register OR. Rotary magnet 503 isaccordingly operated to rotate the wipers 511-514, inclusive, intoengagement with the desired set of bank contacts in the selected level,which in this case is the set 564 which is allotted to ofiice #2. Thejumper, associated with the bank contact on which the first code-digitwiper511 lands is connected at the other end to the third impulse-stopconductor 433, thereby predetermining that the first code digit to besent out will be the digit 3.

The bank contact on which the second code-digit wiper 512 lands isVconnected by means of a jumper to the skip conductor, therebypredetermining that the second code-digit position will be skipped, thetrunking layout being such that the desired office is reached at the endof the first code digit.

The bank contact upon which the grounded wiper 513 lands is connected bymeans of the associated jumper to conductor 542. Aocordingly, relay 609,Fig. 11, energizes over conductor 542 and disconnects the last liveassociated bank contacts from the impulsestop conductors 426-440,inclusive, and connects them to the first five impulse stop conductors531-536, inclusive. The thousands digits 6-0, inclusive, are therebycombined with the thousands digits 1-5, inclusive.

The bank contact upon which the grounded wiper 514 lands is connected bymeans of the associated jumper to conductor 545. Accordingly, relays 523and 525 energize in series over conductor 545. Relay 523, uponenergizing, disconnects the stop conductor 355 from the skip conductorat armature 530 and connects it to the third impulse-stop conductor 433,thereby predeterinining that a series of three impulses will betransmitted after the thousands selector has been operated and beforethe registered hundreds digit is sent out. Relay 525, upon energizing,disconnects conductor 356 from the skip conductor at armature 532 andconnects it to the wiper 604 o1' the thousands register DR-1. Relay 525also connects the con.- ductors 549 and 550, associated with the firstand second halves, respectively, ofthe bank contacts of wiper 604, tothe skip conductor and to the eleventh impulse stop conductor 541,respectively. Accordingly, it is predetermined that the setting of thethousands register DR-l will determine whether or not an extra series ofeleven impulses shall be sent out between the vertical and rotaryoperations ofthe connector switch to be used in com leting the call.

Byt e conjoint a-ction of relays 301 and 302, Fig. 8, in response to thesecond office digit, the wipers ot the sequence switch S are againadvanced one step. Wiper 309 at this time closes the impulse circuit,thereby starting the sender SEN, Fig. 9, to send out the iirst digitinthe omce code. However, before the description yot this operation istaken up, the description of the registration of the desired number willbe completed.

When the calling subscriber at substation A manipulates his callingdevice in accordance with the first subscriber digit 5 in the desirednumber, the tive impulses ot" current which are transmitted over thepreviously traced circuit to wiper 310 ot' the sequence switch S, F ig.8, are sent over conductor 331 to the stepping magnet 601 ot' the lirstdigit register Dlt-1, F ig. 11. Accordingly,-the wipers 604 and 605 ot'the digit register DR-l are rotated into engagement with thecorresponding set of bank contacts.

When the calling subscriber manipulates his calling device in accordancewith the second subscriber digit 0, the ten impulses of currenttherebyfproduced, are transmitted over the above traced circuit to wiper310 ot the sequence switch S and thence by way of conductor 332` to thestepping magnet ot the second digit register Dlt-2. Accordingly, thewiper 606 is advanced into engagement with its last bank contact.

When y the calling subscriber dials the third subscriber digit, tenimpulses of cui'` rent are delivered over the impulse circuit to Wiper310 ot the sequence switch S, and are thence transmitted by way ofconductor 333 to the stepping magnet of the third digit register IDR-3,resulting in the wiper 607 being advanced into engagement with its lastcontact. l v

lhen thecalling subscriber dials the next and last digit 0 ot thenumber, ten impulses of current are delivered through wiper 310 of thesequence switch S and conductor 334 to the stepping magnet ot thetoni-th digit register Dlt-4, resulting in Vthe wiper 603 being steppedinto engagenientwith the last bank contact.

At the endet the registration of the last subscriber digit, the wipers309 and 310 ot the sequence switch` S are advanced another stepand thewiper 310 engages a dead contact,'and accordingly the said wipers remainin this-position until the director is freed and tlierapparatus restoredto normal.

The Voperation et the sending equipment will now be taken up. ltwill beremembered that upon the cessation ot the second series ot impulsesdelivered to the director, which` impulses were transmitted to rotarymagnet 503 ot the otiice register OR, wipers 303 and 310 Vot theiinpulsecontrol sequence switch S were Aadvanced into engagement with the thirdset ot bank contacts. vWhen this occurs, wiper 309 connects the groundedinterrupter leadV over conductor 428 and through the resting contact anarmature 426 to sending relay 403. As soon as interrupter 303 closesthecircuit of sending relay 403, the latter eneroifes and opens a point ini g the outgoing control circuit at armature 418. This, however, doesnot produce any result owing to the tact that armature 418 and itscontact are shunted by armature 421 and its contact. As a furtherresultof the energization or sending relay 403, it closes at armature419 a circuit for stepping magnet 406 of the sender SEN. Magnet 406thereupon energizes and moves the associated pawl into engagement withanother notch in the wiper-driving ratchet wheel, but does not move thewipers 407 and 408. Upon the subsequent deenergization ot sending relay403, it opens the circuit of stepping magnet ot the sender at armature419, whereupon stepping magnet 406 deenergizes and advances the wipers407 and 408 into engagement with the iirst setof bank contacts. liper40T engages a grounded contact thereby closing a circuit tor pick-uprelay 404. iJick-up relay 404, upon energizing, prepares a lockingcircuit tor stop relay 405 at armature 422; closes a circuit torstepping magnet 311 of the sending control sequence switch S at armature420, and at armature 421 removes the shunt trom around armature418 andits contact so as to permit an interruption to be produced in theoutgoing control circuit upon each ot the subsequent energizations otthe 'sending relay 403.

At the end of the third interruption produced in the outgoing controlcircuit, sending relay 403 deenergizes and opens the circuit of steppingmagnet 406 ot the sender, whereupon the wipers 40T and 408 are advancedinto engagement with the fourth set of bank contacts. l.Viper408thercupon completes the tollowing circuit: troni ground by w ot' the'stop-conductor-cone trol wiper 513 of the sendingecontrcl quent-eswitch S', the iii-st code-digit stop conductor 341, the .lirst viper:511 ot the oiiice register OR, the bank contact upon which it isstanding, the associated juiniVi-r-i', the third impulse-stop conductor433, the fourth contact in the bank ot wiper 408 ot the sender, and stoprelay '205 to battery. Stop relay 405, upon energizing, completes alocking circuit toI itsel't at armature 427, disconnect-s thedccnergized sending relay 403 at armature 426, and armature .i opens thecircuit oit stepping magnet 311 ot the sending control sequence switchS, whereupon stepping magnet 311 deenergizes and advances the wipers 312and 313 into engagement with the second set ot bank contacts. TWhen thisoccurs, the stop-conductor-control wiper 313 applies ground to thesecond` code-digt-stop conductor 343, thereby closing a circuit over thesecond liu Cil

code-digit wiper y512, the bank contact upon which it is standing, theassociated jumper, the ship conductor, and thence to battery by way ol'the interrupter contacts and magnet 311 of the sending control sequenceswitch S. Stepping magnet 311 according ly energizes again andinterrupts its own circuit, whereupon it deenergizes and advances thewipers 311 andy 312 into engagement Awith the third set of'bank contactsin readiness to send out the lirst subscriber digit.

As a further result of the above pointed out energization oi stop relay405 of the sender, it cla-:esk at armature 424 a circuit through thebank contact iipon which wiper 407 is standing, and wiper 407 forstepping magnet 406 through the associated interrupter contacts.ificcordingly, the magnet 406 operates in the manner of a. buzzer untilthe wipers 407 and 408 are stepped to the last set ot bank contacts.'Vhen this occurs, wiper 407 is no longer grounded and the steppingoperation ceases. Furthermore, wiper 407, in passing oli the lastgrounded bank contact, opens the circuit of pick-up relay 404. Pick-uprelay 404, however, is slow acting and does not energize immediately.

In the selector D, Fig. 5, each time the outgoing control circuit isinterrupted by sending relay 403, as pointed out above, line relay 65cle-energizes and closes a circuit for vertical magnet 72 as follows:from ground by way oi" resting Contact and armature 84, armature 7 6 andits resting contact, armature 7 8; and its working Contact, serie.Jrelay 6,7, and vertical magnet 72 to battery. By the successiveoperations of vert-ical magnet 72, the wipers 861-88, inclusive,of theselector D are raised step-by step until they stand opposite the desiredlevel of bank contacts. Relay 67 is energized in series with verticalmagnet 72 upon the first impulse of current passing through it and,being slow acting, maintains its armature attracted throughout thevertical movement. Relay 67, upon energizing, prepares at armature 79 acircuit which is completed through interrupter contacts 74 and oiinormal contacts 75 ttor stepping relay 68 responsive to the closure ofoil normal contacts 75 when the switch shaft moves from its normalposition. Upon energizing, stepping relay 68 closes a locking circuitfor it-selt' at armature 80, and at armature 8l prepares a circuit forrotary magnet 73.

Upon the cessation of the vertical movement, slow acting series relay 67decnergizes and completes the circuit of rotary magnet 73 at armature79. Rotary magnet- 73 thereupon energizes and advances the switch wipers86-88, inclusive, into engagement withV the first set of bank contactsin the selected level, and near the end of its stroke,

opens the circuit of stepping relay 6,8 at in*- terrup'ter contacts 74.Relay 68 accordingly deenergizes and opens the circuit of rotary magnet7 3 at armature 81, whereupon rotary magnet 73 deenergizes also andagain closes its interrupter contacts. In case the trunk terminating inthe first set off bank contacts is idle, switching relay 69 energizesimma diately. Assuming the trunk to be busy, however', switching relay69 is shortV eircuited by the ground potential encountered on the busytest Contact by test wiper 87 and does not energize. VUnder theseconditions, test relay 68 is again energized, this time through testwiper 87, and,'in addition to closing its usual locking circuit atarmature 80, it again completes the circuit oi rotary magnet 73 atari'nature 81, whereupon the' wipers are advanced another step in theabove manner. i

This alternate operation of stepping relay 68 and rotary magnet 73continues as de scribed until an idle trunk is reached, which trunk itwill be assumed is the one terminating in bank contacts 89491,inclusive, and comprising conductors 92-94, inclusive'. lhen such idletrunk reached, switching relay 6,9, being no longer short circuited,energizes in series with stepping relay -68 and from the groundedrelease trunk conductor 63. Stepping rela-y 68, however, is notoperatively energized at this time on account o't the high 'resistanceof switching relay 69. Switching relay 69, upon energizing, opens thetest circuit and prepares the holding circuit .at armature 83; removesground from armature 76 ofl line relay 65 at armature 84, therebyopening the circuit of release relay 66; and at armatures 82 and 85disconnects conductors 62 and 64 from relay 65 and extends them by wayof wipers 86 and 8.8, bank contacts 89 and 91, and trunk conductors 92and 94 to the windings of the line relay ofv the thousands selector E inthe desired olice, which, in this case, is office #2. Accordingly, thevline and release re-v lays of the selector E (not shown) energize andthe latter prepares the switch for oper-V ation in the usual manner.

Returning now to the director, slow acting pick-up relay 404 of thesender, Fig. 9, finally deenergizes and opensV the locking circuit ofthe slow actin' stop relay 405 at armature 422. Accordingly, slow actingrelay 405 deenergizes after an interval and again connects up sendingrelay 403 at armature 406, whereupon the sender is started to send outthe irst subscriber digit 5. It may be pointed out at this time thatthe'interval required for relays 404 and 405 to fallback one aiter theother, as described above, is utilized by the selector D in 'performingthe change-over and trunk-hunting operations above described.

The sender has ben restarted, as vpointed out. above, and is now sendingout the first subscriber digit 5, and when the fifth interruption in theoutgoing control circuit occurs, the following deenergization of sendingrelay 4:03 is followed by the advance of the wipers 407 and A103 intoengagement with the sixth set of bank contacts, whereupon stop relay 405energizes over the following circuit: from ground by way'of the stopconductor control 'iper 313 of the sending control sequence switch S',Fig. 8, the third associated bank contact, the lirst subscriber digitstop conductor 351.r wiper 605 of the digit register DR*1, the sixthassociated banl; contac, the right-hand armature of relay 610 and itsresting contact, the fifth impulse-stop conductor 135, the correspondingcontact in the sender banlnwiper 403, and stop relay l105 to battery.Responsive to the enero'ization of stop relay 405, the first subscriberdigit is terminated in the usual manner and the wipers of the sequenceswitch S are advanced one step responsive to the opening of the circuitof stepping magnet 311 at armature L1-23.

In the called exchange, the selector E raises its wipers opposite thefifth level re s nonsive to the operation of the sender above escribedand then selects an idle trunk, which trunk, it will be assumed, is theone comprising conductors 101403,y inclusive, and extending to the'wiper selecting hundreds selector F. Accordingly, line relay 122 of theselector F is energized'over the calling loop and closes at armature 131the usual circuitl for release relay 123. Release relay 123 thereuponenergizes and places ground lon vrelease trunk conductor 102 at armature132; opens a4 pointin the circuit of release magnet 162 at armature 133;and at armature 134shunts the lower winding of relay 101 around offnormal contacts 163 for a purpose to be described hereinafter.

In the director, the wipers of the sendingcontrol sequence switch S arenew in en gagement with the fourth set of associated bank contacts andground is applied to the special wiper selecting stop conductor 355 bythe stop-conductor-control wiper 313. rlhis stopping ground is extendedthrough armature 527 and its resting contact and armature y530 and itsworking contact (relay 523 having been energized as hereinbefore pointedout), tothe third impulse-stop conductor 433. Accordingly, the nextdigit to be sent out is the digit 3 which is sent out in the usualmanner and which is terminated upon the energization of stop relay 105from the ground potential applied to the third impulse stop conductor433 over the above traced circuit. At the end of the transmissionof'this wiper selecting digit 3, the wipers of the sequence switch S areadvanced another step in the usual manner and ground is' applied to thehundreds-di git stop conductor 352 by the stop-conductor-control wiper313.

ln the selector 14", Fig. 6, line relay 102 is d-eenergized three timesmomentarily, rcsponsive to the sending out of the above mentioned wiperselecting digit and, accordingly, three impulses of current aretransmitted at armature 31 to vertical magnet 16e by way of armature 133and its working Contact and series relay 12"1. 'By the operation ofvertical magnet 164, the shaft of the switch is raised three steps andcarries the wipers opposite the third level of banli contacts. Theswitch shaft also engages the shaft springs and closes the contacts10e'. and 105 which are both placed so as to be operated when the shaftis raised three steps, as is indicated on the drawing. Upon theclosureof the shaft-spring contacts 105, relay 127 is energized from thegrounded release trunk conductor 102 and through the normally closedcontacts controlled by armature 129 of relay 121. Upon energizing, relay127 locks itself to the grounded release trunk conductor 102 at armature1415, and at armatures 1113, 14A, and 1416 disconnects the upper set ofwipers and connects up the lower set of wipers. Slow acting series relay121 is energized throughout the vertical movement and closes a point inthe circuit ofstepping relay 125. Stepping relay 125, however, does notenergize on account of the fact that its circuiti is open at armature130 of relay 121. Series relay 12st also maintains the ground potentialdisconnected from the shaft contacts 104 at armature 135.

At the end of the vertical movement, series relay 124 deenergizesv andcloses at armature 135 a circuit for release magnet 162 whichincludesthe shaft spring contacts 1011, resting contact andar1miture`123, and off normal contacts 163. 1t will be noted that thelower winding of relay 121 is included in this circuit except for thefact that it is shunted by olf normal contacts 163. itesponsive to theclosure of this circuit, release magnet 162 energizcs and closes atarmature 161 a locking circuit for itself independent of armature 135and the shaft spring contacts 1011#l Release magnet- 102 also permitsthe shaft of the wipers of the switch to be' restored to normalposition, and when the shaft reaches its normal position, it removes theshunt from around the lower winding of relay 121 by opening the offnormal contacts 163. -When this occurs, relay 121 energizes; closes alocking circuit for itself and opens a point in the initial circuit ofrelay 127 at armature 129; closes a point in the circuit of steppingrelay 125 at armature 130; and at armature 123 opens the circuit of 'itslower winding and release magnet 163, whereupon release magnet 163becomes deenergized.

The net result oit' the transmission of the preliminary digit 3, it willbe noted, is that the selectorI F has been raised to the third level,whereupon the wiper switching relay 127 became energized anddisconnected the upper cet oi' wipers and connected up the lower set oitwipers, and the shaft and wipers have been reshircd to normalpreparatory to the reception of the hundreds digit.

In the director, the hundreds digit 0 is now transmitted and isterminated responsive to the energization of stop relay 405 over the'following circuit: from ground by way oi the step conductor controlwiper 313 oit the sequence switch S, F 8, the fifth associated bankContact, the hundreds digit stop conductor 352, wiper 606 oi' the seconddigit register Dlt-2, the eleventh associated bank contact, the tenthimpulse stop conductor 440, the associated contact in the sender bank,wiper 408, and stop relay 405 to battery. Responsive to the energizationoi stop relay 405, the circuit of stepping magnet 311 of the sequenceswitch S is opened at armature 423 and the wipers 312 and 313 areadvanced into engagen'ient with the sixth set of bank cont cts.

In the selector F, Fig. 6, line relay 122 is deenergized ten timesmomentarily in resaonse to the above described operation ot the senderand, upon each deenergization, closes the previously traced circuit ofvertical magnet 164. By the ope 'ation of vertical magnet 164, theswitch wipers are raised opposite the tenth level of bank contacts.Series relay 124 isy again maintained energized throughout the verticalmovemen and in conjunction with olf normal contacts 167, which closeupon the first vertical step, completes at armature 136 a circuitthrough armature 130 and its working contact and interrupter contacts166 ior stepping relay 125. Stepping relay 125, upon energizing, closesa locking circuit 'for itself at armature 137, and at armature 13S`prepares a circuit for rotary magnet 165. F rom this point, theoperation of the selector F' is identical with the operation of theselector D previously described.

kBriefly, the rotary movement is initiated upon the decneroization ofslow acting series relay 124 at the end of the vertical movement andcontinues until an idle trunk is reached by the wipers 150-152,inclusive, which trunk it will be assumed is the one comprisingconductors 153455, inclusive, and ending to the connector HL. When thisoccurs, switching relay 126, being no longer short circuited, energizcsin series with stepping relay 125 and switches the connection through tothe selected set of wipers at armatures 139, 140 and 142, and atarmature 141 opens the circuit oi release relay 123 which subsequentlydeenergizes and removes thelower winding of relay 121 from around oli'normal contacts 163 so as to prevent the said lower winding lromintertering with the regular releasing operation ot' the selector whichis to take place subsequently.

In the connector H2, line relay 201 now energizes over the calling loopresponsive to the above mentioned seizure oi" the associated trunk andcloses at armature 209 a circuit tor release relay 203. thereuponei'iergizes; opens a point in the circuit oif release magnet 231 andlrepares a circuit for vertical magnet 230 at armature 21.2; prepares acircuit lor the upper winding oit switching relay 203 and for busy relay206 at armature 2li; and at arn'iature 210 places ground on releasetrunk conductor 154. Y

In the director, when the sender is restarted, it continues to operateuntil ten impulses oi? current have been sent ont, at which time stoprelay 405 is energized over the following circuit; from ground by way etstop-condactor-control wiper 313 oif the sequence switch S', the sixthassociated bank Contact, the tens digit stop conductor 353, wiper 60T ofthe third subscriber digit register Dlt-3 the eleventh associated bankcontact, the tenth impulse stop conductor 440, thi associated contact ofthe sender bank, wiper 408, and relay 405 to battery. The energizationof stop relay 405 terminates the tens digit in the usual manner and alsoresults in the advance of the sequence switch C into engagement with thenext set ot bank contacts, whereupon stop-conductor-control wiper 313applies ground to the special stop conductor 356, which stop conductorconnected through armature 352 and its working contact (relay 525 havingbeen energized in series with relay 523 as above pointed ont), andconductor 548 to wiper l604 ot the `lirst or thousands digitregisterDil-1.

Since wiper 604 has been advanced into engagement with the sixthassociated bank contact in response to the calling of the thousand:digit 5, as above pointed out, the ground potential is extended by wiper604 to conductor 549 and thence through armature 533 and its workingcontact to the skip conductor resulting in the usual operation of thesequence switch S to automatically advance its wipers to the neXt set ofbankcontacts. Accordingly, the extra set of eleven preliminary impulsescannot be delivered to the connector' H2 between the, tens and unitsdigits, and the upper set of wipers willl therefore be used to completethe connection which is to be extended to the line of substation Awhichterminates in the upper bank ci? connector H2. 1

In the connector H2, line relay 201 deenergizes ten times mon'ientarilyresponsive to the above operation of the sender and, upon eachdeenergization, completes a circuit for eiease relay 203 .'1-

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vertical magnet 230, the circuit at the time of its lirst closure beingas follows: from ground by way of armature 209 and its resting Contact,armature 212 and its working contact, the contact of olf normal spring229 and said spring, series relay 204, and vertical magnet 230 tobattery. By the operation of vertical magnet 230, the shaft and wipersof the connector H2 are raised step by step until the latter standopposite the tenth level of bank contacts. Relay 204 is energized inseries with vertical magnet 230 and, being slow acting, maintains itsarmature 213 attracted throughout the vertical operation and maintainsits own circuit and that kof vertical magnet 230 intact after the off tooperate after the usual `interval between digits and transmits the lastdigit in the number.' This digit is terminated upon the energization ofstop relay 405 of the sender through the stop-conductor-control wiper513, the eighth associated bank contact, the units-digit stop conductor354, wiper 608, the bank contactupon which it is standing, theassociated impulse-stop conductor, and

wiper 408 of the sender. Upon the energization of stop relay 405, thelast digit in the number is terminated and the wipers of the sequenceswitch S are .again advanced one step in the usual manner. At this time,the wiper 313 grounds the last contact in its bank and accordinglyIgrounds conductor 59,

ythereby closing a circuit which extends from ground by way of the saidconductor 59, the

' associated contact inthe bank of wiper 55 of the secondary switch SS,Fig. 5, wiper 55, working contact and armature 51, armature 39 and itsworking contact, and switching relay 37 to battery. Switching relay 37of the trunk circuit TC thereupon energizes and locks itself to thegrounded release' trunk conductor 63 at armature 44, an'd at armatures43 and 45, disconnects conductors 25 and 27 from the windings of linerelay 35 and extends them to trunk conductors 62 and 64, respectively,thereby bridging lthe calling line across said conductors 62 and 64 andat the same time disconnecting the control circuit of the sender fromacross the said conductors. Line relay deenergizes responsive to beingdisconnected at armatures 43 and 45 and opens the circuit of releaserelay 36 at armature 38. Release relay 36 accordingly decnergizes afteran interval and removes ground fromrelease trunk conductor 63 atarmature. 40, leaving the established connection to be held up by theground 'potentiele applied te release' trunk condii'ctr 154 by releaserelay 203 of the connector H2, Fig. 7. Release relay 36 of the trunkcircuit TCA also opens the circuit of switching relay 46 of thesecondary switch SS at armature 41, whereupon switching relay 46deenergizes A and disconnects its wipers, thereby freeing the director.

In the director, release relay 402 deenergizes responsive to the removalof ground from the release trunk conductor 58 when the director is freedas pointed out above and closes at armature 416 the normal restoringcircuit of the sender SEN which is effective only in case the directoris freed while the sender is not in its normal position. As a furtherresult of the deenergization of release relay 402, it closes at armature415 the normal restoring circuit of the sending control sequence switch'S, whereupon the wipers 312 and 313 are advanced the remaining step totheir normal position, magnet 313 being energized through wiper 312. Asa still further result of the deenergization of release relay 402, itapplies ground to release conductor 401 at armature 417, thereby closinga circuit for the release magnet of the sequenceswitch S, for therelease magnet of the office register OR, and for the release magnets ofdigit registers DR-1-DR-4, inclusive. Then this occurs, release magnet307 of the sequence switch S energizes through the associated off normalcontacts 308, and the wipers 309 and 310 are restored to normal positionin the usual manner, whereupon the circuit of' release magnet 307 isopened at olf normal contacts 308. Release magnet 502 of the o'Hiceregister OR is energiied through the associated 0H normal contacts 501`whereupon the wipers 511-514, linclusive, are restored to normalposition in the usual manner. The digit registers DR-1DR-4, inclusive,are restored to normal position in the same manner as the sequenceswitch S.

Responsive to the restoration of the wipers of the ofi-ice register OR-to normal, relays 523 and 525, Fig. 10, and relay 609, Fig. 11,deenergize.

The various pieces of apparatus of the director have been restored totheir normal positions and the director is now in readiness to handle'another call.

In the connector H2, Fig. 7, line relay 201 is momentarily deenergizedfor each of the interruptions produced inits circuit by the hereinbeforedescribed operation of the sender in sending out the last digit of thenumber, and upon each deenergization, line relay 201 closes a circuitfor rotary magnet 232 as follows: from ground by way of armature 209 andits resting contact, armature 212 and its working contact, normallyopened contacts controlled by off ,normal tact, resting contact andarmature 219, armature 220 and its resting Contact, and rotary magnet232 to battery. By the operation of rotary magnet 282, the wipers251-255, inclusive, and the wipers 261-263, inclusive, are rotated stepby step until the former come into engagementwith the bank contacts2511-250, inclusive, ot' the line of substation A. The wipers 261-263,inclusive, it may be pointed out, do not engage any of the associatedbank contacts owing to the fact that the extra series ot' elevenimpulses were not transmitted between the tens and units digits.

Relay 207 of the connector is energized 1n multiple with rotary magnet232 and, being slow acting, maintains its armature attracted throughoutthe rotary movement. Upon energizing, relay 207 disconnects testwiper252 trom the upper winding ot' switching relay 208 and connects it tobusy relay 206, and at armature 222 places a shunt around armature 219and its resting contact as a precaution against the circuit of therotary magnet being opened at armature 21,9v in case busy relay 20Genergizes during the rotary movement due to wiper 252 passing overgrounded test contacts.

Assuming the called line to be busy, busy relay 206 is energized throughtest wiper 252` and from a ground potential encounteredvon the busy testcontact 255 and prepares a locking circuit for itseli:l at armature 218;opens a point. in the circuit of the rotary magnet at armature 219; andat armature 220 connects the busy lead to the lowerv heavy talkingconductor, thereby sending a busy signalling current back over theestablished connection to the called sub station. Vhen relay 207deenergizes, itdis-- connects rotary magnet 232 'from the impulsecircuit at armature 222 (armature 219 having been operated), and atarmature-221 completes the .locking circuit for busy relay 206 anddisconnects test wiper 262 from the said busy relay.

The calling subscriber, upon hearing the busy tone, replaces hisreceiver, whereupon the established connection released in a` manner tobe explained hereinafter.

In the present case, however, it will. be assumed that the line ofsubstation A is idle when called as herei'nbetore described. in whichcase busy relay 206 is not energized when the wipers 251-253, inclusive,come to rest upon the terminals ot the called line and, when slow actingrelay 207` deenergizes at the end or" the rotary movement, itdisconnects test wiper 252 from the winding of busy relay 206 andconnects it to the upper winding of switching relay 208 at armature 221,thereby closing a circuit for switching relay 208 as follows: fromground by way of the working` contact and armature 211, ar-

mature 218 and its resting contact, upper` winding ot switching relay208, resting contact and armature 221, test wiper 252, test contact 255,and thence to battery by way o1' the switching relay and stepping magnetof the associated line switch (not shown), which line switch-may be thesame as the line switch C, associated with the line ot substation A.Responsive to the closure ot this circuit, the switching relay ot' thecalled line switch energizes part way in the usual manner anddisconnects the bridge across the line conductors thereat. Y

In the connector H2, switching relay 208 energizes over the above tracedcircuit and at its lightly adjusted armature 221 closes a lockingcircuit for its lower winding; disconnects rotary magnet and slow actingrelay 207 at armature 220; places direct ground on the test wiper atarmature 224; and at armature 223 and 227 connects up the line wipers,whereupon ringing current is projected out over the called line to ring`the bridged bell at the called. substation. This ringingfcurrent returnsby way ot the upper line wiper 251 tobattery by way ol' the upperwinding of ring cut-oil3 relay 205.

Then the called subscriber responds to the ringing of his bell byremoving his receiver, a direct current bridge is closed across theassociated line conductors, whereupon ring cutoll` relay 2.05 energizes;closes a locking circuit for itself at its lightly adjusted armature 216and at armatures 214 and 217 disconnects the line wipers from its ownupper winding` and the generator lead and connects them instead to thewindings of the back bridge battery feed impedance 202. rllhe desiredconnection is now completed` and the subscribers may converse asdesired.

Then the conversation is completed, the two subscribers replace theirreceivers. lVhen the receiver is replaced at the called substation A',talking battery merely ceases to flow in the called line, but when there` ceiver is replaced at substation A, the circuit ofy line relay 201of the connector H2 is opened, whereupon line relay 201- deenergizes andopens the circuit ot release relay 203. Release relay 203, uponenergizing aitter an interval, removes ground from release trunkconductor 154 at armature 210,- and at armature 212 completes a circuitfor release magnet 231. through off `normal contacts 228, whereupon theswitch is restored to normal position in the usual manner,

Responsive to the removal of the ground potential from conductor 154,ring-cut-otl" relay 205 and switching relay 208 of the conf neetor H,relays 121, 126, and 127 of the selectorF, the switching relay notshown) Vof the selector E, switching relay 69 of the selector D,switching relay 37 of the trunk circuit. TC, and switching relay 14 ofthe line switch C all deenergize. Responsive to further that, when thedeenergization of the relays mentioned, the associate-d switches arereleased in the usual manner. The entire connection is now released andthe apparatus involved therein may now be used in setting' up asubsequent connection.

In order to explain how the necessary translation is eiected when thethousands digit is above 5, and in order to explain how the klower setot wipers of the connector H2, Fig. 7, are used when such translation ofthe office digit takes place, it will now be assumed that the subscriberat substation A desires to converse with the subscriber at substationA2, Fig. 7. lt will be assumed the receiver is removed at substation A,the line switch C selects the t-runk circuit TG, and that the secondaryswitch SS selects the director shown in the drawings. Accordingly,responsive to the manipulation of the calling device in accordance withthe cnice digits belonging to oiice #2', the wipers ot the oliiceregister OR, Fig. 10, are raised opposite the desired level in thehereinbefore described manner, and are then brought into engagement withthe set of bank contacts 564 ot the oiiice #2 as before explained. v

Responsive to the manipulation of the calling device at substation A inaccordance with the four subscriber digits 0000, the digit registersDR-1-DR-4, inclusive, are set upon the corresponding bank contacts inthe usual manner.

. The ofice code is at this time sent out in the same manner ashereinbetore described, (operating the selector D to seize the selectorE), after which the stop conductor control wiper 313 of the sendingcontrol sequence switch S is ladvanced into engagement .with its thirdbank contact, thereby placing ground through the thousands digit stopconductor 255 of the wiper 605,l which as explained hereinbefore hasbeen advanced ten steps and is now in engagement with the last of itsbank contacts. Since relay 609, Fig. 11, is energized through the lowerwiper of' the office register and through conductor 542, the lastcontact in the bank of wiper 605, is now disconnected from the tenthimpulse stop conductor 440 and is connected.

instead to the ifth impulse stop conductor 435. Accordingly, thethousands digit to be sent out is the thousands digit 5, which causesthe selector E', Fig. `6, to be raised to the iifth level toselect ahundreds selector in the corresponding group, the selector F', forexample, in the same manner as described hereinbefore.

Since relay 523, Fig. 10, is energized as in the preceding example whenthe substation A was called, the wiper-selecting digit 3 is delivered tothe selector F', causing it to select the lower set ot wipers in thesame manner as before. Following this, the hunlll quence switchS areadvanced into engagey ment with the seventh bank contact, in which thespecial stop conductor 356 terminates. Ground is accordingly extendedover stopconductor 356 and through armature 532 and its working contact(relay 525 being energized in series with relay 523), to wiper 604 ofthe thousands-digit register Dlt-1, by way of conductor 548. Since wiper604 is standing on the last halt of itsv bank instead of the iirst half,the ground potential is not extended to the skip conductor as it was inthe case just described when the called subscriber was the one atsubstation A', but is extended instead through co-nductor 550 andarmature 534V and itsl working contact, to the eleventh impulse-stopconductor 441. Accordingly, eleven interruptions are produced in the circuit ot line relay 201 of the connector H by the sender which results inthe wipers 251-253, inclusive, being rotated entirely over theassociated bank 'of contacts, and in the wipers 261-263, inclusive,being brought within one step of the associated bank ot contacts inreadiness to be brought into engagement with the desired set ot contactsresponsive to the transmission of the units digit. In the director.wiper 313 of the sending cont-rol sequence switch S is advanced intoengagement with the eighth associatedv bank contact in the usual manner,following the transmission of the above mentioned series of elevenimpulses, and the last digit O is s et out in the hereinbe- Jforedescribed manner, whereupon the sequence switch S is again advanced andthe director is released and the connection switched through asdescribed hereinbefore.

In the connector H2, Fig. 7, the wipers 261-263, inclusive, are advancedintovengagement with the bank contacts 2644266, inclusive, responsive tothe sending out ot' the lastdigit 0. From this point on the operation isas described hereinbefore.

Reterring now particularly to Fig. 10, it will be noted that when thisdirector is used in completing a call to a line in otiice #2, Fig. 2,the wiper 513 completes a circuit over one ot the contacts 563, theassociated jumper, and conductor 542 for the trans lating relay 609, asis the case when the ofiice #2 is called. Wiper 514, however, instead ofcompleting a circuit over conductor 543 for the relays 523 and 525 inseries, as is the case when o'flice #2 iscalled, completes a circuitover conductor 544 for the relays 524 and 525 in series. Accordingly,the wiper selecting digit to be delivered to a hundreds selector, suchas the hundreds selector F, Figs. 2 and 6, is two instead of three,armature 531 of relay 524 connecting conductor 355 to the secondimpulse-stop conductor 532 instead of to Vthe third im pulse-stopconductor 433, as is the case when relay 523 is energized. Otherwise thenumber received by the director and intended for oflice #2 is handledjust the same as described hereinbefore for a number received by thedirector a-ndintended for oiiice 2. #When a call is received by thedirector which is intended for oiiice #1, Fig. 1` the i director mustnot send out a wiper selecting digit just prior to the sending out ofthe hundreds digit, on account of the fact thatv the hundreds selectorF, Fig. 1, has only one set of wipers. Accordingly, the fourth bankcontact in the set allotted to ofiice #1, Fig. 10, instead of beingconnected to either of the conductors 544 and 545, is connected toconductor 543, and relay 525 is energized alone and performs thehereinbefore mentioned function of shifting the circuits so that thesending out of the eXtra series of eleven preliminary impulses by thetens and units digits is dependent upon the thousands digit dialled.

When a call is received by the director shown, that is intended for a.line in oflice #3, Fig. 3, the wipers 511-514, inclusive, are broughtinto engagement with the bank contacts 565, Fig. 10, as is indicated inthe drawings. In this case, the bank contact on which the third wiper513 of the office register OR stands, is connected by means of a Yjumperto the conductor 542, as explained in connection with the precedingexample, so as to pull up the tianslatingY relay 609 in order to sendout all of the calls through the first five levels of the selector E',Fig. 3. In addition to the above, the bank contact engaged by the fourthwiper 514 of the otlice register OR is connected by means of a jumper toconductor 546, so as to energize relay 522. Relay 522, upon energizing,disconnects conductor 355 from the skip conductor at armature 527 andextends itl by way of conductor 548 to wiper 604 of the thousands-digitregister DR-l. Relay 522 also connects the two conductors 549 and 550coming from the contacts in the bank of wiper 604 to the second andthird impulsestop conductors 432 and 433, respectively. Accordingly,after the thousands digit is transmitted. and before the hundreds digitis transmitted, either the digit 2 or the digit 3` will be transmittedin order to; effect the correct wiper selection at the twenty grouphundreds selector F2. This wiper selection is controlled in accordancewith the thoustands digit registered by the thousandsdigit registerDlt-1, and if the thousands digit is from 1 to 5, inclusive, thewiperselecting digit 2 is sent out to selectthe upper set of wipers: ofthe selector F2, and if the thousands-digit register is from 6 to 0,inclusive, the wiper-selecting digit 3 is sent out, resulting in thelower set of wipers of the selector F 2, Fig. 3, being selected.

It will' be noted that in this case. it is not necessary to make anyarrangements for controlling the selection of the wipers of theconnectors, such as connectors H3 and Hgowing to the fact that theseconnectors are of theI 100 line. type, having only a single set ofwipers.

When the director shown is'used in completing a call to oice #4, Fig.4.f the wipers of the otlice register ORv are broughtV into engagementwith the bank contacts 566 whose third and fourth contacts are jumperedin exactly the same way as the corresponding contacts associated withoflice #3. Accordingly, when the callV is trunked to the selector E3 inaccordance with the junipering of the contacts engaged by the wipers 511and 512, the number is transmitted in the same manner as explained inconnection with office #3 and the upper set of wipers of the connectorin use is employed to eomplete the connection, the upper set of wipersof the connectors H5' and H6 corresponding to the single set of wipersof the connectors H3 and H4.

When, however, thel present director .is used to complete a connectionto otlice #4', the wipers of the office register are brought intoengagement with the bank contacts '567, whereupon relays 521 and 522 areenergized in series over conductor 547. Relay 522 performs the functionabove described in connection with the trunking of calls to o'liices #3and #4 and relay 521 performs the added function of disconnectingconductor 356 from the skip conductor and connecting it to the eleventhimpulse-stop conductor 441, thereby preedetermining that thewiper-selecting digit 11 is to be sent out after the transmission of thetens digit and before the transmission of the units digit, so as tocause the lower set of wipe-rs of the connector in use to be usedy incompleting the connec tion instead of the upper set, as is` the casewhen relay 522 is energized alone.

As point-ed out hereinbefore, either of the layouts shown in Figs. 2Vand 4, when du.- plicated by the addition of the necessary switchesaccessible to the sixth to tenth levels, inclusive, of the. thousandsselectors, provides for four 10,000-1ine oices reached.

